Molecular studies in flexor tendon wound healing: the role of basic fibroblast growth factor gene expression

Basic fibroblast growth factor (bFGF) is a cytokine that plays a fundamental role in angiogenesis. This study examines bFGF messenger RNA (mRNA) expression in a rabbit flexor tendon wound healing model. Thirty-four New Zealand white rabbit forepaws underwent transection and repair of the middle digit flexor digitorum profundus tendon in zone II. Tendons were harvested at increasing time intervals and analyzed by in situ hybridization and immunohistochemistry. Few tenocytes and tendon sheath cells expressed bFGF mRNA in unwounded tendons. In contrast, tendons subjected to transection and repair exhibited an increased signal for bFGF mRNA in both resident tenocytes concentrated along the epitenon and infiltrating fibroblasts and inflammatory cells from the tendon sheath. These data demonstrate that (1) normal tenocytes and tendon sheath cells are capable of bFGF production, (2) bFGF mRNA is upregulated in the tendon wound environment, and (3) the upregulation of this angiogenic cytokine occurs in tenocytes as well as in tendon sheath fibroblasts and inflammatory cells.     

A prospective study of flexor tendon repair in zone 5

A prospective study of postoperative mobilization of flexor tendon repairs in zone 5 was conducted over a 2-year period between 1994 and 1996 using a controlled active motion (active extension-active flexion) regimen of mobilization. Fifty-two patients, who had a total of 151 flexor digitorum superficialis (FDS) and 103 flexor digitorum profundus (FDP) divisions, were available for review at a mean follow-up of 10 months. Of the 161 fingers with division of one or both flexor tendons, 66% exhibited independent FDS function and 90% achieved good or excellent results of digital range of motion. No rupture of an FDP tendon repair occurred during the study period. The data allowed us to define a new method of classifying the results of treatment of these injuries in terms of the injured wrists as a whole and not simply as a series of isolated observations for each individual finger with divided flexor tendons. The results of recovery of independent FDS action and range of finger movement achieved for injuries in which the flexors of all four fingers had been divided indicate a statistically significant interdependence of injuries of finger flexors of adjacent fingers at the wrist. Multivariate analysis showed the presence of a "spaghetti wrist" injury to have a significant adverse effect on the recovery of the independent FDS action but not on the recovery of the digital range of motion.     

Anatomical factors in displacement of the superficial digital flexor tendon in dogs

The superficial digital flexor muscles of 12 adult dogs were investigated to get informations on the possible anatomical factors which could play a role in the displacement of the superficial digital flexor tendon in dogs. It was seen that the lateral displacement of the superficial digital flexor tendon, tearing its medial attachment, was a result of the weaker medial attachment on the tuber calcanei and the change of the angulation between the calcaneus, insertion and origin points of the muscle in flexed hind limb.     

Division of flexor tendons causes progressive degradation of tendon matrix in rabbits

Deep flexor tendons of 30 rabbits were divided at the ankle level. The effects of unloading on the synthesis and content of matrix components, the synthesis of DNA, and dry weight were investigated. The ability of the tendons to synthesize collagen during short-term culture and the contents of matrix components decreased inversely to the time of unloading. 12 weeks following division, the fibrocartilagnious segments had lost 2/5 of their dry weight, 2/3 of proteoglycan and 1/3 of collagen and non-collagen protein content. Less pronounced losses were observed in the non-fibrocartilaginous segments. A transient increase in cell proliferation in both types of segments was found. These findings indicate that divided flexor tendons undergo a progressive degradation, degradation, which may have implications for delayed suture of deep flexor tendon injuries.     

Cyclic testing of flexor tendon repairs: an in vitro biomechanical study

Forty cadaveric flexor digitorum profundus tendons were repaired using the Tajima, Halsted, Silfverskiold, or Savage techniques. The tendons were cyclically loaded in sets of 4,000 cycles beginning at 25 N and increasing by 10-N increments until failure occurred. Gap formation was continuously monitored with an extensiometer. Only the Savage repair group consistently withstood 4,000 cycles of 25-N loading, with respect to 2-mm gap formation and repair rupture. Tendon repairs subjected to cyclic loading demonstrated gap formation and repair rupture at lower loads than with static testing. Of the methods of flexor tendon repair tested, only the Savage technique could withstand simulated early active motion.     

Rupture of the flexor tendon of the hand caused by tuberculosis

A 47 years-old man presented an atraumatic, spontaneous index flexor tendons rupture. This patient has been treated two years ago for a pulmonary tuberculosis. At surgery, the flexor tendons were infiltrated by a granuloma. Histologic examination was compatible with tuberculosis sequelae. According to literature review, this is the second reported case of a tendon rupture due to tuberculosis granuloma.     

Tendon repair using flexor tendon splints: an experimental study

Mechanical strength of tendon repair using Dacron tendon splints across the laceration site were evaluated in human cadaver profundus tendons; the splints were placed both on the dorsal surface and internally within the tendon substance. Comparison was made to modified Kessler, Becker, and Savage repair techniques. Ultimate tensile strength was 2.55 kgf for the Kessler, 3.00 kgf for the Becker, 8.29 kgf for the Savage, 8.46 kgf for the internal tendon splint, and 8.10 kgf for the dorsal tendon splint; the Savage and both Tendon Splints techniques had significant higher tensile strength than the Kessler and Becker. Gap strength was 1.44 kgf for the Kessler, 2.22 kgf for the Becker, 2.45 kgf for the Savage, 2.05 kgf for internal tendon splint, and 3.15 kgf for the dorsal tendon splint. The dorsal tendon splint technique showed significant greater gap strength than the other four techniques. There was no significant difference in the magnitude of the gap during cyclic testing of these techniques; however, three of seven Kessler repairs failed and one of six Becker repairs failed. The results of these cadaver studies suggest that both tendon splint repair techniques are comparable to the Savage and may have sufficient strength to allow postoperative active motion against minimal resistance. Further in vivo testing is in order.     

Variations of the flexor digitorum superficialis tendon of the little finger

The use of 131I doses of several mCi for scans can stun the thyrocytes and thyroid cancer cells, whereas the usual dose (300 microCi) of 123I does not. We compared the diagnostic accuracy of the 123I (300 microCi) scans and that of 131I (3-10 mCi) scans in 155 patients. The diagnostic accuracy of a 123I scan in detecting functioning thyroid remnant/metastasis was 89.5% (77/86 scans) and that of a 131I scan was 92.9% (39/42) in 6 week-postoperative patients (p = 0.750). For radioablation therapy follow-up patients, the diagnostic accuracy of 123I in determining presence or absence of functioning remnant or metastasis was 69.4% (25/36) and that of 131I was 92.5% (49/53) with a p value of 0.079. The success rates for complete ablation of functioning tissue after radioiodine therapy administered after diagnostic 123I and after 131I were 72% (34/47) and 56% (24/43), respectively, with a p value of 0.125. Our study indicates the following: 1) for the first postoperative evaluation, the diagnostic accuracy of the 123I scan was essentially equal to that of the 131I scan, and the success rate of radioablation therapy appears to be better than 123I scan; and 2) for postablation follow-up surveys, the 131I scan appears to be better but carries the risk of stunning the functioning cells.     

Bowstring injury of the flexor tendon pulley system: MR imaging

OBJECTIVE. The flexor tendon pulley system is often ruptured when a flexed finger is forcibly extended. In the acute phase, soft-tissue swelling and pain often make clinical evaluation difficult. These pulleys are not constantly visualized on MR imaging. Rupture of the pulley system can be inferred by observing bow stringing of the underlying flexor tendons when MR imaging is obtained with the finger in flexion. Our objective is to describe the flexor tendon pulley system and present our MR technique.     

Magnetic resonance imaging scanning in the diagnosis of zone II flexor tendon rupture

This study was undertaken to determine the usefulness of magnetic resonance imaging (MRI) in the diagnosis of flexor tendon rupture in patients who had prior surgery. Magnetic resonance imaging scans were performed on 11 digits (16 tendons) with the clinical diagnosis of flexor tendon rupture. Clinical suspicion correlated with MRI and surgical findings. Clinical examination yielded a 60% accuracy in diagnosis. MRI differentiated rupture from adhesions with a 100% accuracy rate. The MRI scan is a valuable tool in diagnosing tendon ruptures and may help reduce the incidence of unnecessary tendon explorations.     

Simultaneous dislocation of both interphalangeal joints and flexor tendon tear in a finger

A case in which the death of a 2-year-old male child was the result of an acute intoxication with chloral hydrate, lidocaine, and nitrous oxide is presented. Trichloroethanol (TCE), the primary metabolite of chloral hydrate, was qualitatively detected by the Fujiwara reaction. Quantitation of TCE was carried out by gas chromatography-mass spectrometry (GC-MS) with the following results: plasma, 79.0 mg/L; urine, 31.0 mg/L; gastric contents, 454.0 mg/L; bile, 111.0 mg/L; vitreous, 40.2 mg/L; cerebrospinal fluid (CSF), 68.3 mg/L; and liver, 164 mg/kg. Lidocaine was quantitated by GC analysis using nitrogen-phosphorus detection with the following results: plasma, 11.9 mg/L; urine, 3.7 mg/L; gastric contents, 15.3 mg/L; bile, 19.0 mg/L; vitreous, 17.8 mg/L; CSF, 9.4 mg/L; and liver, 19.0 mg/kg. Nitrous oxide was quantitated in the blood with a value of 4.4 mL/L.     

Atraumatic retrieval of the proximal end of a severed digital flexor tendon

A suction catheter technique is suggested as the next procedure of choice when proximal digital "milking" with wrist flexion fails to deliver the proximal end of the flexor tendon severed within the digital sheath.     

Treatment routines of flexor tendon injuries. Results of a questionnaire study

A questionnaire was distributed to the surgical departments of all Norwegian hospitals, asking about the routines for treating flexor tendon injuries in 1990. The response rate was 95.5%. Some of the smaller hospitals did their own flexor tendon surgery, but referred patients with a complex injury to a hospital with better trained hand surgeons. In 1990, a total of 573 flexor tendon repairs were carried out in Norwegian hospitals. After surgery, all patients had a cast or a brace for a period ranging from three to six weeks. Most of the hospitals used dynamic traction and had a programme for training the patient, which was supervised by a hand therapist. Active flexion was allowed from two to eight weeks after the operation. We recommend referral of all flexor tendon injuries in zone II to a surgical unit with trained hand surgeons. After surgery, a programme including dynamic traction and training supervised by the surgeon and a hand therapist should be compulsory.     

In vivo tendon forces correlate with activity level and remain bounded: evidence in a rabbit flexor tendon model

The purpose of this study is to assess the feasibility, clinical tolerance, local control, and survival rates using a combined-modality treatment program of intraoperative radiation, chemotherapy, and external beam radiation for the management of patients with pancreatic cancer. One hundred eighty patients with biopsy-proven adenocarcinoma of the pancreas have been treated by a single surgical practice between 1979 and 1992. Of these, 105 had locally advanced but unresectable primary tumors (stages 2 and 3). All patients were treated with a program of multimodality therapy, including surgery, chemotherapy, and radiation therapy. Three groups were identified. Group I (33 patients) received intraoperative radiation therapy (IORT) as part of their treatment. Group II (43 patients) received intraoperative radiation in the form of iodine-125 (I-125) implantation. Group III (29 patients) received no intraoperative radiation. All three groups were comparably similar with respect to age at presentation, amount of preoperative weight loss, preoperative symptoms, and tumor location. Overall perioperative mortality was 4.8 per cent (five patients), with no difference between groups noted. Perioperative complications occurred in 32 (30.4%) of the 105 patients. Complications occurred in only 18.1 per cent of patients in Group I (IORT), compared with 39.5 per cent of Group II (I-125) patients (P < 0.01). Group III patients (no intraoperative radiation) experienced complications in 31.0 per cent of cases (P = 0.09 vs Group I). Actuarial survival was 18 months for Group I (IORT) versus 15 months for Group II (I-125). One- and 2-year actuarial survival rates were 60 and 17 per cent for patients in Group I (IORT) and 56 and 19 per cent for Group II (I-125). Actuarial local control rates for patients receiving IORT (Group I) was 70 per cent at 2 years. Patients with pancreatic cancer historically have poor survival and local control rates despite aggressive chemotherapy and radiation. The addition of intraoperative radiation to the combined modality management of pancreatic cancer offers markedly improved survival rates and local control with minimal morbidity for patients with unresectable disease. Intraoperative radiation in the form of IORT can be delivered with a significantly fewer complications than I-125 seed implantation.     

Flexor tendon ruptures in the rheumatoid hand: bilateral flexor pollicis longus rupture

In a 42-year-old male with a 15-year history of rheumatoid arthritis, bilateral rupture of the flexor pollicis longus was associated with subluxation with radial deviation of the carpus and increased angulation of the tendon in relation to the navicular. Flexor tenosynovitis in the rheumatoid hand may present as carpal tunnel syndrome or ruptured flexor tendons. The condition is associated with invasive rheumatoid granulation tissue, vasculitis, ischemic necrosis due to compartment compression, and attrition rupture due to navicular bony protuberance.     

Rupture of the flexor pollicis longus tendon at the musculotendinous junction in a bowler

Traumatic rupture of the flexor tendons at the musculotendinous junction is rare. A case of flexor pollicis longus tendon rupture at the musculotendinous junction is described. The mechanism of the tendon injury appears to be longitudinal traction on the contracted muscle during delivery of a bowling ball.     

An audit of flexor tendon injuries in zone II and its influence on management

This paper reports the results of a one-year audit of flexor tendon injuries in zone II managed in a controlled mobilization program. It discusses the rationale for the use of this program and compares results with those of other units. On the basis of these results, the authors suggest that rehabilitation programs for patients with this type of injury should be tailored to individual needs and that trends in management should be carefully evaluated before implementation.     

Extracellular matrices in peritendinous connective tissue after surgical injury to the chicken flexor tendon

Dichlorotriazinyl aminofluorescein (DTAF) has been used to stain corneal stromal collagen as part of in vivo animal experiments for many years. Toxicity of this drug, if present, might alter the observed wound healing. To determine if this drug has any deleterious effect on keratocytes, we evaluated it in vitro. Human keratocytes prepared in 24-well plates were exposed to varying concentrations of DTAF (10(-4), 10(-3), 10(-2), 1, 10, 10(2) micrograms/ml). Exposure times of 1 hour and 24 hours at each concentration of DTAF were evaluated. The cell number was measured 1 and 3 days after initiation of exposure to DTAF using a Coulter counter. Keratocyte proliferation was not affected by 1-hour exposure to DTAF, but keratocyte proliferation measured 3 days after initiation of exposure to DTAF for 24 hours was inhibited in a dose-dependent manner (p = 0.02) and was significantly inhibited at concentrations of 10 and 100 micrograms/ml (p < 0.05). Fluorescent microscopy showed binding of DTAF to keratocytes. We have demonstrated that prolonged exposure to DTAF inhibits proliferation of cultured keratocytes. These results suggest that DTAF-induced cytotoxicity may alter net production of collagen in the corneal stroma in animal models.     

Rupture or stress injury of the flexor tendon pulleys? Early diagnosis with MRI

In node-positive breast carcinoma, the presence of tumour cells in the efferent vessels (EV) of the axillary nodes (positive EV status) was shown to be of poor prognosis in 1979. Later the presence of nodal micrometastases was also related to survival. This report describes a new subgroup in this system that is of potential therapeutic interest. It consisted of the 40% of the EV-positive cases with micrometastases (< 0.2 cm2) in their nodes, in addition to nodes with macrometastases. In them the difference in prognosis associated with EV status no longer held. Their prognosis did not differ markedly from that in the EV-negative patients. In the absence of such 'additional' micrometastases, the prognostic difference was still highly significant. There was also some indication that the presence of micrometastases consisting of embolic tumour growth alone may be associated with early death in EV-negative cases, in keeping with the prognosis in cases with lone micrometastases.